Generation of lucky nos from a given list of nos.

FIRSTLY SUPPOSE CONSIDER 10 ITEMS
1 2 3 4 5 6 7 8 9 10
FIRSTLY EACH 2ND ELEMENT IS DELETED THEN WE GET
1 3 5 7 9
THEN EACH 3RD ELEMENT IS DELETED
1 3 7 9
THEN EACH 4TH ELEMENT WILL BE DELETED THEN WE GET
1 3 7
NOW EACH 5TH ELEMENT IS DELETED AS THERE IS NO 5TH ITEM WE GET
1 3 7
THE ABOVE NOS
1 3 7
ARE CALLED LUCKY NOS